I use a prong. Harley and I had a long discussion about this previously, since unfortunatley, most pinch's are used wrong.
I use it correctly, and use it for easier time communicating. My dog can work in a flat, however, he's still a puppy, so I still prefer the pinch, we also have a martingale we use too.
I hate choke chains, I've never seen any good come from them other than dogs that are showing in them, since they are actually put on the right point of their neck.

Aidan, my previous was a corgi-we got doxie, GSD, GSD puppy, chihuahua, yorkie, and my favorite, a Westie....
My current has been called a lab, greyhound, great dane, rott, doberman, doverman, and pit bull, etc.
I get tons of stupid questions. If it's honest, I reply honest, if it's just stupid, I reply stupid....

OP, an independant breed isn't a bad thing, you can work it into a positive.
My Beauceron is one of those breeds that do things on his terms.
From my understanding of Schipperke, they will do anything for their person, which is the same that we have with Geronimo.
(I have a friend with Beaucerons that used to have Schipperkes, and she'd go back to them in a heartbeat. Said they were insanely easy to get to understand what she wanted, just like Beauc's)

The difference between a 'regular' dog and an independant....
Typically, basic stuff is pointless.

Geronimo understands what I'm asking by way of basic obedience. He typically won't do anything about it however.
He thinks repetitions of sit, down, etc, is silly.
That's normal for a Beauc. I have a friend with one, who when she took him to a basic obedience ring (she'd competed for years with other breeds) her Beauc took off, ran around the room barking at people.
If they don't want to do it, they don't.
But, he'll do anything that is necessary to take care of me, his charge.
In fact, we've been doing some looking at Geronimo's task work.
We taught him 3 things..... JUST 3.
The rest, (8 total at 8 months, and I'm not kidding) he saw a need, he found a way to meet the need, we told him we liked it.
They are super-smart, and willing to do what THEY view necessary for their people.
My friend who had Schipps says they are similar to a Beauceron. Hopefully someone with a Schipp comes in and helps more, but jut want you to see that just because they are independant doesn't mean they are bad for sd work.

As a person with PTSD, let me remind you there are many of us out there with PTSD, and nowhere to go.
THe programs don't always want to train for us, we're afraid of telling anyone, and we are utterly alone.

I'm a woman with 20 years of abuse at the hand of my family.
I know women and men who have gone thru similar and worse events.
The minute we say PTSD, everyone assumes we've served, when we say no, we are discounted because we weren't overseas.

It's sad that we can't get the help we need, because of not going overseas?
It's GREAT that you're helping someone who's served, and I am for that all the way, but don't forget there are other victims out there, victims like me, who were forced to live in abuse, or rape victims, or people who've witnessed murders..
We are victims too, and we need help just the same as the veterans do.

Guest, not sure what you mean......
As in are they showing and using the Sds?
yes.
In fact, 2 of which were just at the Beauc specialty shows with their SD/show dogs, had their gear sitting ringside, and would take them in the ring, or handled depending on the situation, and then they'd leave the ring, and go back to work.

I know of quite a few who breed, and show their service dogs.
Not just in my breed of choice, but others as well.
It does happen alot, but because so many people get nasty about it, most of them just don't tell anyone.
Geronimo's mom is a service dog, as is his dad.

I don't feel like going into a ton of writing tonight, (LONG day...)
But for me, the main factors were breed and that I have multiple issues that I need the dog to work.
I chose the breed because they are VERY intelligent, and can think all on their own, which was important for me.
(at 8 months, he knows 7 or 8 tasks, mostly self-taught when he saw a need)
The size was also important, I needed a dog at LEAST 26-27 inches tall, but didn't want the HUGE dog. His weight-range is easier to deal with than some of the larger dog breeds (dad tops at 100, mom's smaller at 70 lbs)
The beauce's make very good multi-taskers, which played a large role in picking OT and PT.
He does psd, is picking up on medical alert I didn't even know about, hearing alerts, mobility, and taught himself to retrieve.
I LOVE it!

I'm sorry I don't have anything but anecdotal, but I have a friend with a schnauzer, she resuced him from the pound, and asked me to groom him.
He has so much hair in his ears he honestly could not hear well, and he had a bad ear infection, and ear wax build up.
We plucked it all, and within a week, his ears had cleared up, and his hearing had improved drastically.

I will always clear the ears out, I've seen it work wonders on dogs.
I've seen dogs do so much better after their ears can breathe

Unfortunately Onxy, not all breeders care.....
I know nothing of the Dobe stuff, but I've seen many different breeders, of many different breeds of dogs.
Some will do some testing, some will do none, some will do all of it.

Unfortunately, most regular people don't research enough on what could be a potential with the breeds....